Dishwasher drain and screen apparatus



Aug. 16, 1955 J. STANITZ T AL DISHWASHER DRAIN AND SCREEN APPARATUS m u 1 m wn m a m mi k s B H m ML wn c w h E0 3 w nJ J a 4 u M L Aug. 16, 1955 TA ET AL 2,715,408

DISHWASHER DRAIN AND SCREEN APPARATUS Original Filed Aug. '7, 1950 3 Sheets-Sheet 2 J ggventors aw was adult? F 1/9; 4 Myron .b'lmwmcin w JohnL.Hw12e '5; 1

Gttornegs Aug. 16, 1955 J sTANlTZ ET AL DISHWASHER DRAIN AND SCREEN APPARATUS 3 Sheets-Sheet 3 Original Filed Aug.

n J 0 S M ML m q k C 0 m 5 M United States Patent 0 DISHWASHER DRAIN AND SCREEN APPARATUS Jacques Stanitz, Warren, lviyron E. Uiiman, 3n, Canfield,

and John L. Habe, Cleveland, Ohio, assignors to Mull'ms Manufacturing Corporation, Salem, Ohio, a corporation of New York Qriglnal application August 7, 195%), Serial No. 178,054, new Patent No. 2,692,665, dated October 26, 1954. Divided and this application April 3, 1953, Serial No. 346,602

3 Claims. (Cl. 134-111) The invention relates generally to dishwashing machines, and to a novel dishwasher having a revolving central spray column for jetting or spraying washing liquid or other washing medium outwardly uniformly throughout the height of the racked or stacked dishes within the dishwasher, and relates more particularly to a drain and screen construction for such a dishwasher; and this application is a division of our co-pending application, Serial No. 178,054, now Patent No. 2,692,605.

Many conventional dishwashers employ a rotary impellet having spiral blades at the bottom of the tub or vat containing the dishes, and when this impeller is rotated at high speeds it throws the cleansing water from the bottom portion of the tub upwardly and outwardly against a basket of dishes in the tub. The water thrown by the impeller strikes the dishes at the bottom of the basket with full force, but the water striking the dishes at the top of the basket has to travel a relatively great distance and is deflected from one dish to another while passing through the basket. The result is that only a small portion of the water reaches the top dishes and strikes them with very little force. While some of the water is thrown by the impeller radially outward under the dishes and is deflected by the tub wall inwardly against the dishes, this water travels a long distance and has largely spent its force before it reaches the dishes in the upper part of the basket.

Consequently, with the impeller type of dishwasher, the dishes at the top of the basket are either not thoroughly washed or the washing cycle required to wash and rinse the dishes is greatly prolonged.

Other prior dishwashers have attempted to use revolving sprays or revolving baskets of one kind or another, but these have not been satisfactory because in construction where the sprays are located at the bottom of the tub the water does not thoroughly cleanse the dishes at the top of the basket. To clean the surface of a dish most effectively, the sprays should strike the surface at a small angle so as to scrub or scour the food therefrom, but with these radial sprays if a dish is placed so that its front surface is properly impinged by the sprays, then the back of the dish is turned away from the sprays and is not properly impinged thereby, even though the sprays and dishes rotate relative to each other.

it is an object of the present invention to provide an improved dishwasher having a novel revolving central spray column and improved drain and strainer means associated therewith for thoroughly and rapidly cleaning dishes arranged around the column.

Another object is to provide a dishwasher having a novel revolving spray column which accomplishes substantially uniform spray pressure and impingement on all dishes within the washer from water circulated through improved drain and strainer means.

Another object is to provide a dishwasher having a novel revolving spray column with sprays of screened circulated washing liquid arranged to strike directly against both 2,715,408 Patented Aug. 16, 1955 21 front and back surfaces of all dishes so as to thoroughly cleanse the same.

A further object is to provide a dishwasher having a novel revolving spray column discharging groups of sprays which strike the dishes in progressively downwardly areas so as to wash them from the top downwardly with screened circulated washing liquid.

Another object is to provide a dishwasher having a novel revolving spray column which is rotated at a regulated speed by the reaction of the cleaned circulated washing liquid sprays discharging therefrom.

Another object is to provide a dishwasher having a novel revolving column in which the spray ports are so arranged as to give a substantially balanced torque reaction on opposite sides of the column during rotation from screened circulating washing liquid jetted therefrom.

A further object is to provide a dishwasher having a novel revolving spray column which is economically constructed and easily installed or removed without the aid of tools, and permitting access to associated improved strainer means.

A still further object is to provide a dishwasher having a novel revolving spray column journaled on a stationary inner standpipe extending upward from a sump and strainer means, the standpipe having water distributing means within the column.

These and other objects are accomplished by the parts, constructions, arrangements, combinations and sub-combinations comprising the present invention, a preferred embodiment of which is shown in the accompanying drawings as exemplifying the best known mode of carrying out the invention, the invention being described in detail in the accompanying specification and the scope of the invention being defined in the appended claims.

in general terms, the dishwasher comprising the preser invention may be set forth as including a tub with a central standpipe mounted therein and having water supply holes distributed throughout its height, there being a water outlet or drain in the tub adjacent the base of the standpipe and a strainer around the standpipe and covering said outlet, a pump circulating water from said outlet into said standpipe, a preferably polygonal spray column journaled on said standpipe and having laterally spaced series of vertically spaced spray ports arranged to jet cleansing liquid against progressively downward areas of both sides of dishes arranged around said column and to rotate the column by the torque reaction of the sprays, and a dish holding basket for bolting the dishes arranged around the column.

Referring to the drawings forming part hereof in which a preferred embodiment of the invention is shown by way of example;

Figure l is a vertical sectional view through a dishwasher embodying the present invention, as on line 1li, Fig. 3;

Fig. 2 is an enlarged vertical sectional view showing the novel strainer construction in the tub;

Fig. 3 is a plan sectional view somewhat enlarged, as on line 33, Fig. 1;

Fig. 4 is a diagrammatic view showing the manner in which the sprays of liquid discharged or jetted from the revolving spray column strike a plate which is held in the dish basket within the tub;

Fig. 5 is an enlarged vertical sectional view through the revolving spray column;

Fig. 6 is a plan View of the top cap thereof; and

Fig. 7 is a developed view showing the exterior of the four sides of the rectangular spray column.

Similar numerals refer to similar parts throughout the drawings.

The novel dishwasher of the present invention includes a preferably cylindrical tub or vat indicated generally at which is preferably formed from sheet metal in a well known manner. The tub may be supported within a suitable sheet metal cabinet indicated generally at 11 which is provided with a suitable base (not shown) for resting on the floor. The cabinet 11 may house the dishwasher tub alone, or it may be extended laterally to enclose a sink so as to provide a combination sink and dishwasher cabinet.

If the operation of the dishwasher is to be automatic, the lower part of the cabinet 11 may enclose the necessary timer mechanism, as well as the driving motor for the circulating pump and the necessary control valves, electric switches, etc. In Fig. 1 a centrifugal circulating pump is indicated at 12, and the drive shaft 13 of the pump may be coupled or operatively connected to a suitable driving motor (not shown).

The bottom wall 10:: of the tube 10 slopes inwardly downward to a central washing liquid collecting well 14, and a hollow stationary pipe or standpipe projects through the center of the well 14 vertically upward within the tub 10. The standpipe 15 is preferably mounted in a supporting flange 16 which is clamped to the bottom wall of the well by means of a nut 17, there being washers 18 on both sides of the bottom wall to make a liquid-tight joint around the supporting or mounting flange. The bottom end of the supporting or mounting flange 16 is connected to the outlet of the pump 12 by means of a short hose connection 19 coupled to the supporting flange 16 and pump outlet by hose clamps 20.

A drain fitting indicated generally at 21 is connected at its upper end to one side of the well 14, and at its lower end to the intake 22 of the pump, by means of a hose section 23 and hose clamps 24. The drain fitting 21 is provided with a valve housing 25 which communicates with a lateral connection 26 for connecting to the usual waste outlet, and the valve housing 25 encloses a suitable drain valve which may be automatically or manually controlled as desired. When the drain valve is closed and the pump is operating, liquid in the tub will be drawn into the pump through the drain 21 and circulated or recirculated by the pump into the standpipe 15. When the pump is not operating and the drain valve is open, the

liquid in the tub will drain into the waste through the connection 26.

The side wall 10b of the tub 10 may be removably supported on the cabinet by providing an outer downturned rim flange 27 at the upper edge of the tub wall engaging over and resting on the upper edge of a curved inner flange 28 of the tub support 29 which is welded or otherwise secured to the cabinet. As shown, the flange 27 of the tub may be secured to the supporting flange 28 by bolts 30.

The dishwasher top 31 preferably includes an inner shoulder 32 connecting with a downwardly extending flange 33 which extends within and overlaps the upper portion of the tub, and the bottom edge of the flange 33' is turned outwardly at 33a toward the tub wall to provide a narrow annular vent between the tube and dishwasher top as indicated at 34. A gasket 35 may be provided between the dishwasher top 31 and a horizontal flange 36 on the top of the cabinetwall. The lid 37 for enclosing the tub of the dishwasher during the washing operation is adapted to fit within the dishwasher top 31 and to rest on the shoulder 32, there being a sealing gasket 38 on the bottom edge of the lid for resting on the shoulder.

The vent 34 between the tub and top flange 33 provides for the escape of vapors within the tub without allowing the washing liquid to escape. Otherwise, the vapor pressure might build up within the tub and make it difficult to close the lid or tend to bulge the lid if it were locked in closed position. Building codes in some 10- calities. require venting of tub or vat in dishwashing machines.

Preferably, the dishwasher is provided with an upper basket 40 for holding glasses and cups and the like, and

with a lower basket indicated generally at 41 for holding plates and dishes. The upper basket is preferably hung from the shoulder 32 by angular bracket arms 42 and the lower basket has angular wire feet 43 for supporting it on the bottom wall of the tub, as shown in Fig. 1.

The central standpipe 15 projects vertically upward through the center of the tub and terminates adjacent to the lid 37. The standpipe is provided with a closed end by a preferably conical top end 45, and a preferably square hollow column or tubular sleeve 46 is telescoped over and rotatably supported on the point of said conical end 45. Preferably, the column 46 has a closed end formed by a cap 47 secured in its upper end, with a center rivet 48 having a conical recess 48a therein. The

conical surfaces and 48a are formed with difierent angles so that the point of standpipe top end 45 contacts the innermost point of conical recess 48a to form the bearing or suspension for the column 46. The rivet 48 may be copper or bronze, and the conical point on the standpipe may be stainless steel to provide a good bearing suspension with a minimum of friction.

Preferably, a hood 49 secured by the rivet 48 within the cap 47 extends downwardly around the top of the standpipe with a slight clearance to provide an air seal which acts to prevent food particles such as coffee grounds from getting into the conical bearing suspension. The cap 47 is provided with pressure relieving holes 50 located around the hood 49 to prevent a pressure surge of liquid within the column from lifting the column off the conical bearing point of the standpipe.

The bottom of the column 46 is closed by an annular cap or bushing 51 which provides a bearing guide for the column around the standpipe 15, the sleeve or column 46 thus enclosing and being spaced from the side walls of the pipe 15. The inner flange 52 of the cap 51 is spaced radially outwardly from the standpipe sufliciently to provide a slight clearance between the cap and standpipe. In order to prevent food particles and the like from lodging in the clearance space between the bottom cap 51 and standpipe, the standpipe is provided midway of the flange 52 with circumferentially spaced holes 53 for discharging water from the standpipe radially outward at that point and thus flushing the food particles away from the clearance space in both directions.

Within the column 46, the standpipe is provided with vertically spaced supply holes or orifices 54, and these holes may be distributed as shown substantially throughout the height of the standpipe so as to uniformly distribute the supply of cleansing liquid from the standpipe throughout the height of the column 46 so that the cleansing liquid is supplied to all of the spray ports in the column substantially simultaneously. The combined area of the holes 54 is substantially equal to the cross sectional area of the standpipe 15, so that no back pressure is created within the standpipe. The holes 54 are considerably larger than the holes in the strainer indicated generally at 55, which is located around the base of the standpipe within the top portion of the well 14, so that no food particles large enough to clog the holes 54 can pass through the strainer into the pump and thence into the standpipe.

While the column 46 is preferably square in cross section, it will be understood that the column may be fiat sided or polygonal in cross section with 2, 3, 4 or more sides, without departing from the scope of the invention. The preferred arrangement of the ports for spraying or jetting the cleansing liquid outwardly from the column 46 is best shown in the developed view of Fig. 7 wherein the adjoining sides are designated as A, B, C and D. Each side has two laterally spaced vertical rows of' ports located closely adjacent to the opposite edges of the side, the ports in each room being spaced longitudinally of the sleeve or column 46.

The ports are indicated at 56 and as shown are all of the same diameter, being drilled or punched perpendicular to the surface of the side of the column in which they are located. Different sized holes or ports 56 may be used when desired and the ports may be angled with respect to horizontal or vertical where desired. Thus two laterally spaced vertical rows of sprays or jets are discharged outwardly in parallel or angled directions from each side of the column 46, and as shown in Fig. 4, as the column rotates, each two rows of sprays straddle each dish or plate P supported in the lower basket 41 encircling the column. The combined area of all the ports 56 is slightly less than the cross sectional area of the standpipe.

The ports 56 are arranged with respect to the center of the column so that the reaction from the sprays will rotate the column at a substantially uniform speed in a clockwise direction, and as the column rotates the ports 56 always communicate with the holes 54 in pipe and the laterally spaced rows of sprays will strike or impinge both surfaces of the plates and dishes at various angles, as indicated in Fig. 4. The amount of unbalance or uneven distribution of the ports which causes the clockwise rotation of the column is relatively small, and as shown in Fig. 7, there are nine ports 56b in the left row of the side B and seven ports 56b in the right row on the side B. Similarly, there are eight ports 560 in the left row on the side C and six ports 560 in the right row. Thus the reaction from the greater number of ports in the left rows in these two sides will tend to cause the column to rotate in a clockwise direction, from side A to B to C to D. The number of ports in the two rows 56a in side A is the same and the number of ports in the left row 56d is two less than the number in the right row 56d, so that there will be a slight reaction on the side D tending to rotate the column in a counterclockwise direction, and this will tend to decrease the speed in which the column rotates in a clockwise direction.

As indicated in Figs. 3 and 4, the lower basket 41 is constructed to hold the plates and dishes on edge in spaced apart relation angled slightly from extending truly radially of the tub, and with the front plate edges lying in planes parallel with the vertical centerline of the column, so that as the column 46 rotates, one vertical row of sprays at the leading edge of a side of the column will first impinge the inner part of the top surface of a plate at a slight angle, and as the column rotates, the point of impingement will progressively move toward the outer part of the top surface of the plate. As the leading row of sprays leaves the top surface, the trailing row of sprays strikes the rear surface of the plate and moves across the same, as shown by the positions of the sprays 56b at three successive positions in dotted, full and dot-dash lines in Fig. 4. Thus each pair of rows of sprays being discharged from a side of the column in effect straddles the plate and moves progressively across its surfaces to scour and scrub food particles therefrom.

Referring to Fig. 7, it will be seen that the pattern of the spray ports on the adjoining sides A, B, C and D' of the column is progressively downward in groups so as to follow a helical path around the column. Thus the ports 56:: are located at a higher level than the ports 56b and the ports 56b are higher than the ports 560, the ports 56d being the lowest roup of ports and located at the bottom portion of the column. Hence, as the column rotates, the ports 56a will impinge and in effect wipe across the top portions of dishes located in the basket 41, then the ports 56b to 56d will impinge and wipe across the progressively lower portions or areas of the dishes, so that the successive ports 56a to 56d successively wash the dishes progressively downwardly. The same general pattern is followed by the smaller groups of ports 56a, 56b, 56c and 56d located in the upper portions of the sides A, B, C and D, respectively, for spraying or jetting cleansing liquid outwardly against cups and glasses and the like positioned in the upper basket 40. in Figure l the sprays issuing from the ports 56 are indicated by the same reference numerals as the ports, and the sprays 56b are shown striking across an upper area of the dishes, while the sprays 56d are shown striking across a lower area, and the sprays 56c issuing from the back side would strike an intermediate area of the dishes.

Thus as the column 46 rotates clockwise by the reaction of the sprays, the sprays are discharged from successive sides of the column in a progressively downward spiral pattern, striking progressively downward areas of the dishes in the baskets so as to wash the food particles downwardly therefrom. By locating the revolver column 46 at the center of the tub, all of the dishes are located at substantially short uniform distances from the column so that the sprays strike the dishes with maximum force and do not have to travel increased distances to reach the dishes at the outer portions of the basket, as is the case with dishes in the top of the basket where a bottom impeller is used. Moreover, greater and more uniform action is obtained from the rebound of the sprays from the side of the tub, because each spray travels only throughout a radius of the tub before it strikes the outer wall and is deflected back against the dishes to augment the washing action. The result is that, by actual test, the present novel dishwasher cleanses dishes more thoroughly and more rapidly than any conventional dishwasher of which we are aware.

By using a flat sided or polygonal column, the rows of spray ports are spaced apart laterally a maximum distance with a minimum cross sectional area for the column, and the flat surfaces facilitate drilling or piercing holes at right angles to the surface to provide parallel sprays that will straddle the dishes to more effectively cleanse them.

The helical pattern of the spray ports 56 in the sides of the column 46 is such that the reaction of the sprays is substantially uniform on opposite sides of the column, so that the column is substantially uniformly balanced on its bearing 45 at the top of the standpipe 15 at all times.

In the operation of the novel dishwasher, a desired amount of water is introduced into the tub 10 by means of a supply line 661 communicating with a top inlet 61, and detergent added to make a cleansing solution. The pump 12 is operated to circulate the liquid upwardly through the standpipe and into the column from which it is sprayed or jetted outwardly through the ports 56. As the food particles are washed from the dishes downwardly and inwardly over the tub bottom they are washed onto the strainer 55 which preferably consists of an outer dished section 62 and an elevated inner cup-shaped section 63 which is supported on the support flange 16. Preferably, the outer section has a downwardly curved inner bead 64 which is supported on the outer edge of the cup-shaped section 63. The outer portion of the section 62 is substantially fiat to receive food particles from the bottom wall of the tub at the top of the well 14, and the fiat portion merges with an inner annular groove 65 located below and adjacent to the cup-shaped section 63. Thus as the food particles are washed onto the strainer 62, the coarse particles which are too large to pass through the strainer holes collect in the groove 65 while still allowing the liquid to pass through other strainer holes on both sides of the groove and in the cup-shaped strainer section 63. The strainer sections 62 and 63 are easily removed for cleaning from time to time by merely lifting them upwardly. The section 62 may be lifted up over the column 46 and the section 63 is removed by lifting the column 46 off the standpipe 15 and then lifting the section 63 upwardly over the standpipe.

The novel revolving spray column is easily removed, cleaned, and replaced at any time without the aid of tools and Without requiring any special skill, because its only support is the bearing point 45 on the top of the standpipe from which it is easily lifted and when replaced the conical surface slides easily into the bearing socket 49 held by the rivet 48 to the cap, the bottom cap 51 acting to guide the column vertically downward over the standpipe.

The novel dishwasher cleanses dishes on both sides more thoroughly and rapidly than prior dishwashers, and provides a construction which is extremely economical to make, operate and maintain.

1n the foregoing description, certain terms have been usedfor brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiment of the improved construction illustrated and described herein is by way of example, and the scope of the present invention is not limited to the exact details of construction.

Having now described the invention, the construction, the operation and use of a preferred embodiment thereof, and the advantageous new and useful results obtained thereby; the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the, appended claims.

We claim:

1. In a dishwasher having a tub, a pump for circulating liquid to and from said tub and a dish holding basket in said tub, a hollow perforate standpipe communicating with the outlet of said pump and mounted centrally of said tub and basket, a base at the lower end of the standpipe, a drain opening in the bottom of said tub adjacent said standpipe and connected to the inlet of said pump, and a two piece perforate strainer having an inner cupshaped section and outer dished section surrounding the base of said standpipe and covering said drain opening, said inner cup-shaped section being supported on the base of said standpipe, said outer dished section having a downwardly curved inner bead supported on the outer edge of said cup-shaped section, and said strainer sections each being annular in shape and removable upward of said standpipe.

2. In a dishwasher having a tub, a pump for circulating liquid to and from said tub and a dish holding basket in said tub, a hollow perforate standpipe communicating with the outlet of said pump and mounted centrally of said tub and basket, a drain opening in the bottom of said tub adjacent said standpipe and connected to the inlet of said pump, and a perforate strainer surrounding the base of saidstandpipe and covering said drain opening, said strainer having an inner cup-shaped portion and an outer dished portion, the outer portion having a substantially flat rim merging with an annular groove below said inner cup-shaped portion.

3. In a dishwasher having a tub, a pump for circulating liquid to and from said tub and a dish holding basket'in said tub, a hollow perforate standpipe communicating with the outlet of said pump and mounted centrally of said tub and basket, said tub having a central well around the base of said standpipe and a drain in said well, means connecting said drain to the inlet of said pump, and a perforate strainer surrounding the base of said standpipe within the top of the well, said strainer having an inner elevated portion and an outer dished portion, the outer portion having a substantially flat rim at the level of the tub bottom wall and merging with an annular groove below said inner strainer portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,445,320 Johnson 4 Feb. 13,1923 1,617,021 Mitchell Feb. 8, 1927 1,718,613 Trefiinger June 25, 1929 2,275,189 Wieghart Mar. 3, 1942 

